bingham



B. D.. BINGHAM, OF BOSTGN', MASSACHUSETTS.

Lettere Patent No. 74,041, dated February 4, 1868.

IMPROVEMENT IN WATCHES.

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TO ALL WIIOM IT MAY CONCERN:

Be it known that I, 13.1). BINGHAM, of Boston, in` 'the county ofSuffolk, and State of ,Massaehusett`s have invented certain new anduseful Improvements in Watches; and I -do hereby declare thatthefollowing, taken in connection with the drawings which accompany andform part of this specification, is-a description Vof my inventionsntlicient to enable those skilled in th art to practise it.

In the construction of many watches it is customary to surround the twoplates bctw'een'nnd to whichl the works are fixed, by a peripheral ringwhich 4closes the opening between the plates, and lexcludes dust anddirt which enter through the hinges of the watch-case and otherwise, andinjure the movement. These rings have always extended between the innersurface ofthe plate nearest the'watch-dial to the outer surface of theback plate, and have been confined in placeby small screws in the backplate, having half heads, which,'upon being turned outwardly, projectover the edge of the ring, and hold it flown in contact with the platenearest-the 'd-ial. The use of these screws is objectionable, in thatthey soon get loose, and are apt to-be lost, or to fall into the works;and to sc'construct andsecurely apply the ring as to dispense-with thescrews, is one of the objects of my invention, while the other is toenable me to n'se a. peripheral -ring for .the purpose specified, withwatches now in themarket, whiehI am enabled to do, by making it narrow,and so that it will adjoin the outer corner,

made by-the edge `and under surface of the back plate, instead ofcovering the edge of the back plate, therebeing room in wot-chfcascs asnow made to receive such a narrow ring, but not a ring broad enough tocover the edge of the back plate, or any considerable portion thereof. iv

To carry out my invention, I place or make upon the inner surface of thering, arid at opposite sides thereof, spurs or projections, one of whichmay have a flat surface to project under the back plate on one side,while the opposite one has an upper surface slightly inclined, so thatwhile itslips under the'back plate, and serves to hold the ring down, ityields as the ring` is pressed up, and allows the ring to be removed.

It is in suche provision for holding the ring in place without screws orsimilar fastcniugs, that my invention consists.

The drawing represents, at A and B, the two plates of a watch,surrounded by a ring, applied in accordance with my invention- Ashowing'an edge view of the same, and

B a cross-section ou an enlarged -scale.

C represents the ring in plan.

The mechanism o r Watch-movement isnot shown at all, as it has no directconnection with the invention.

a denotes the cuter or back plate, and b the plate nearest the dial ofan ordinary watch-movement, connected and held in position by pillars inthe usual manner. cis the encompassing-ring, extending from one plate tothe other, at the pcrimeters thereof. Upon opposite sides of this ring:Tare two spurs or projections, d d', preferably made by striking themetal of the ring inwards, as seen at B, though they may be formed byattaching pieces to the inner surface of the ring. One of these spurshas a square shoulder or upper surface, as seen at d', which shoulder,when it is slipped under thc plate a, as seen at B, will prevent thering from rising. The other spur may be inclined on its upper surface,as seen at d, so`that when the ring is in place, as seen at B, it may besprung up from the lower plate, by pressingthc ring directly upwards atthis point,whieh pressure muy be elfected by inserting the point of aknife-blade o1* similar instrument into a slot, e, and prying the ringup. Without such direct upward pressure, however, the surface of theshoulder is suiiciently fiat to hold the ring firmly in place.

In applying the ring it is first carried down over the plate a, on oneside, until the spur d slips under the plate, and then the opposite sideis pressed down around the upper plate, until the spur passes below theplate, when it will spring into place, and the ring is fixed, no otherfastening being required. The ring may be held by one spur only, but theemployment of two is preferred.

It will be obvious that while no jar or accident can remore thc 1'ing,itmay be instantly detached from the plates when desirable, there being noscrews or other fasteniugs to remove.

I claim, in combination with peripheral rings of watches, spurs -orprojections for holding them in place, substantially as described.

Also, making such rings of a width equal to or but slightly exceedingthe space between the inner sur faces ofthe two main plates of a watch,and so as not to cover the larger portion of the thickness of the backplate, for the reason set forth. l I

-B. D. BINGHAM.

Witnesses:

J. B. CROSBY, FRANCIS Gouw.

